scholarly journals Evidence of a ‘dinner bell’ effect from acoustic transmitters in adult Chinook salmon

2020 ◽  
Vol 641 ◽  
pp. 1-11
Author(s):  
AM Wargo Rub ◽  
BP Sandford
Keyword(s):  
Chinook Salmon ◽  
Marine Mammals ◽  
Oncorhynchus Tshawytscha ◽  
Spatial Scales ◽  
California Sea Lions ◽  
Sea Lions ◽  
Acoustic Transmitter ◽  
Archival Tags ◽  
Significant Difference ◽  
Survival Differences

The ‘dinner bell’ hypothesis posits that marine mammals hear or otherwise sense soundwaves produced by acoustic transmitters and use the signal to selectively prey on fish carrying them. A dual tagging study conducted during 2010 and 2011 supports this hypothesis. Results from this study revealed a significant difference in the survival of fish marked with passive integrated transponder (PIT) tags and those marked with active acoustic transmitters. Our objective had been to use both types of tags to study behavior and survival of migrating adult spring Chinook salmon Oncorhynchus tshawytscha at 2 different spatial scales. We tagged fish as they entered the Columbia River, USA, and monitored their survival and progress over a 193 km reach to Bonneville Dam (river km 234), its lowest impoundment. In 2010, estimated survival was 0.74 (95% CI, 0.62-0.86) for PIT-tagged fish but only 0.30 (0.15-0.45) for acoustic-tagged fish. Therefore, in 2011, we included archival tags and a sham acoustic transmitter group to help identify causes of the survival discrepancy. Survival was 0.75 (0.54-0.97) for sham transmitter fish and 0.73 (0.60-0.86) for PIT fish, but only 0.10 (0.00-0.24) for active acoustic transmitter fish. Our study area was replete with harbor seals Phoca vitulina, California sea lions Zalophus californianus, and Steller sea lions Eumetopias jubatus during both years. We suspect the most likely cause of survival differences between tag treatment groups was pinniped predation. Using temperature data from archival tags, we found evidence of such predation and support for a ‘dinner bell’ effect from acoustic transmitter tags.

scholarly journals The Protection of Animals During Warfare

AJIL Unbound ◽  
2017 ◽  
Vol 111 ◽  
pp. 272-276
Author(s):  
Jérôme de Hemptinne
Keyword(s):  
Marine Mammals ◽  
Bottlenose Dolphins ◽  
Rapid Rate ◽  
Human Beings ◽  
Armed Groups ◽  
Military Operations ◽  
Protected Species ◽  
California Sea Lions ◽  
Animal Products ◽  
Sea Lions

In times of war, the first instinct is to relieve the suffering of human beings. Environmental and animal interests are always pushed into the background. However, warfare strongly affects natural resources, including animals, which makes animal issues a matter of great concern. Certain species have been vanishing at a rapid rate because of wars, often with disastrous effects on the food chain and on the ecological balance. Indeed, belligerents rarely take into account the adverse consequences of their military operations on animals. They even take advantage of the chaotic circumstances of war in order to poach protected species and to engage in the trafficking of expensive animal products. While generating billions of dollars each year, such poaching and trafficking allows armed groups to grow and to reinforce their authority over disputed territory. States have also trained, and continue to train, certain animals—principally marine mammals such as bottlenose dolphins and California sea lions—to perform military tasks, like ship and harbor protection, or mine detection and clearance. Millions of horses, mules, donkeys, camels, dogs, and birds are obliged to serve on various fronts (transport, logistics, or communications) and become particularly vulnerable targets.

Changes in adult Chinook salmon (Oncorhynchus tshawytscha) survival within the lower Columbia River amid increasing pinniped abundance

2019 ◽  
Vol 76 (10) ◽  
pp. 1862-1873 ◽  
Author(s):  
A. Michelle Wargo Rub ◽  
Nicholas A. Som ◽  
Mark J. Henderson ◽  
Benjamin P. Sandford ◽  
Donald M. Van Doornik ◽  
...  
Keyword(s):  
Chinook Salmon ◽  
Oncorhynchus Tshawytscha ◽  
Columbia River ◽  
Mixed Effects ◽  
Eumetopias Jubatus ◽  
Considerable Effort ◽  
Alosa Sapidissima ◽  
Sea Lions ◽  
Regression Modelling ◽  
Passive Integrated Transponder Tags

Considerable effort towards conservation has contributed to the recovery of historically depleted pinniped populations worldwide. However, in several locations where pinnipeds have increased, they have been blamed for preventing the recovery of commercially valuable fish species through predation. Prompted by increasing pinniped abundance within the Columbia River (CR), USA, over a 6-year period, we used passive integrated transponder tags to measure the survival of adult spring-run Chinook salmon (Oncorhynchus tshawytscha) through the estuary and lower CR to Bonneville Dam (river kilometre 234). We estimated 51 751 – 224 705 salmon died annually within this reach from sources other than harvest. Mixed-effects logistic regression modelling identified pinniped predation as the most likely source of this mortality. The odds of survival was estimated to decrease by 32% (95% CI: 6%–51%) for every additional 467 sea lions (Zalophus californianus and Eumetopias jubatus) present within the CR and to increase by 32% (95% CI: 8%–61%) for every increase of 1.5 in the log of American shad (Alosa sapidissima), a potential prey item for sea lions.

scholarly journals Geomagnetic field influences upward movement of young Chinook salmon emerging from nests

2018 ◽  
Vol 14 (2) ◽  
pp. 20170752 ◽  
Author(s):  
Nathan F. Putman ◽  
Michelle M. Scanlan ◽  
Amanda M. Pollock ◽  
Joseph P. O'Neil ◽  
Ryan B. Couture ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Chinook Salmon ◽  
Geomagnetic Field ◽  
Oncorhynchus Tshawytscha ◽  
Dimensional Space ◽  
Spatial Scales ◽  
Vertical Component ◽  
Life Cycles ◽  
Upward Movement ◽  
The Magnetic Field

Organisms use a variety of environmental cues to orient their movements in three-dimensional space. Here, we show that the upward movement of young Chinook salmon ( Oncorhynchus tshawytscha ) emerging from gravel nests is influenced by the geomagnetic field. Fish in the ambient geomagnetic field travelled farther upwards through substrate than did fish tested in a field with the vertical component inverted. This suggests that the magnetic field is one of several factors that influences emergence from the gravel, possibly by serving as an orientation cue that helps fish determine which way is up. Moreover, our work indicates that the Oncorhynchus species are sensitive to the magnetic field throughout their life cycles, and that it guides their movements across a range of spatial scales and habitats.

scholarly journals Epidemiological models to control the spread of information in marine mammals

2016 ◽  
Vol 283 (1844) ◽  
pp. 20162037 ◽  
Author(s):  
Zachary A. Schakner ◽  
Michael G. Buhnerkempe ◽  
Mathew J. Tennis ◽  
Robert J. Stansell ◽  
Bjorn K. van der Leeuw ◽  
...  
Keyword(s):  
Marine Mammals ◽  
Foraging Behaviour ◽  
Social Transmission ◽  
Sea Lion ◽  
California Sea Lions ◽  
Sea Lions ◽  
Promising Tool ◽  
Diffusion Analysis ◽  
And Control ◽  
The Impact

Socially transmitted wildlife behaviours that create human–wildlife conflict are an emerging problem for conservation efforts, but also provide a unique opportunity to apply principles of infectious disease control to wildlife management. As an example, California sea lions ( Zalophus californianus ) have learned to exploit concentrations of migratory adult salmonids below the fish ladders at Bonneville Dam, impeding endangered salmonid recovery. Proliferation of this foraging behaviour in the sea lion population has resulted in a controversial culling programme of individual sea lions at the dam, but the impact of such culling remains unclear. To evaluate the effectiveness of current and alternative culling strategies, we used network-based diffusion analysis on a long-term dataset to demonstrate that social transmission is implicated in the increase in dam-foraging behaviour and then studied different culling strategies within an epidemiological model of the behavioural transmission data. We show that current levels of lethal control have substantially reduced the rate of social transmission, but failed to effectively reduce overall sea lion recruitment. Earlier implementation of culling could have substantially reduced the extent of behavioural transmission and, ultimately, resulted in fewer animals being culled. Epidemiological analyses offer a promising tool to understand and control socially transmissible behaviours.

scholarly journals Landlocked Fall Chinook Salmon Egg Survival during Jar and Tray Incubation at a Production Hatchery

2014 ◽  
Vol 7 (1) ◽  
pp. 29-31 ◽  
Author(s):  
Matthew M. Wipf ◽  
Michael E. Barnes ◽  
Patrick A. Nero ◽  
Jill Voorhees
Keyword(s):  
Chinook Salmon ◽  
Oncorhynchus Tshawytscha ◽  
First Year ◽  
Egg Survival ◽  
Significant Difference ◽  
Salmon Eggs ◽  
Second Year

This study compared the survival of landlocked fall Chinook salmon Oncorhynchus tshawytscha eggs incubated in either upwelling jars, either with or without daily formalin treatments, or vertically-stacked trays treated daily with formalin in a production hatchery. In the first year of the study, survival to the eyed-egg stage was significantly greater in eggs incubated in jars without formalin compared to trays, but there was no significant difference in survival to hatch between the treatments. In the second year, there were no significant differences in eggs incubated in trays, in jars without formalin treatments, and in jars with formalin treatments. In the final year, there was no significant difference in eyed-egg survival between eggs incubated in trays and jars without formalin, but survival to hatch was significantly greater in the eggs incubated in jars. Jar incubation is recommended to maximize the survival of landlocked fall Chinook salmon eggs.

scholarly journals Effects of dietary fishmeal substitution with corn gluten meal and poultry meal on growth rate and flesh characteristics of Chinook salmon (Oncorhynchus tshawytscha)

2019 ◽  
Vol 11 (4) ◽  
pp. 325-334
Author(s):  
Katarina H. Doughty ◽  
Shawn R. Garner ◽  
Mark A. Bernards ◽  
John W. Heath ◽  
Bryan D. Neff
Keyword(s):  
Growth Rate ◽  
Chinook Salmon ◽  
Oncorhynchus Tshawytscha ◽  
Growth Period ◽  
Fat Percentage ◽  
Corn Gluten Meal ◽  
Salmon Aquaculture ◽  
Significant Difference ◽  
Corn Gluten ◽  
Total Body

Abstract There is considerable interest in developing diets that maintain growth performance and market appeal for salmon aquaculture while relying less on fishmeal as a major ingredient. Here, we compared growth rate, survival, fat content, tissue colouration and carotenoid levels (astaxanthin) in Chinook salmon (Oncorhynchus tshawytscha) fed two diets. The first diet was a typical commercial salmon diet with 59% fishmeal content, while the second diet reduced the fishmeal content to 15% (75% reduction) and substituted 28% corn gluten meal and 16% poultry meal. Over an approximately 14-month growth period, we found no significant difference between fish fed the high fishmeal or low fishmeal diet in either growth rate or survival. Individuals fed the low fishmeal diet did have 25% higher total body fat percentage than those fed the high fishmeal diet. Individuals fed the low fishmeal diet also had flesh that was significantly less red than fish fed the high fishmeal diet. Carotenoid analysis confirmed that the change in tissue colour was the result of reduced astaxanthin levels in salmon fed the low fishmeal diet. Due to the importance of red tissue colour for the market appeal of salmon, the corn gluten and poultry meal diet is not viable for salmon aquaculture in its present formulation, but our results suggest further modifications to the diet that could mitigate this effect.

Patterns of seabird and marine mammal carcass deposition along the central California coast, 1980–1986

1991 ◽  
Vol 69 (5) ◽  
pp. 1149-1155 ◽  
Author(s):  
James L. Bodkin ◽  
Ronald J. Jameson
Keyword(s):  
Cause Of Death ◽  
Marine Mammal ◽  
Marine Mammals ◽  
Southern Oscillation ◽  
California Sea Lions ◽  
Central California ◽  
Sea Lions ◽  
Common Murres ◽  
Local Patterns ◽  
Species Specific

At monthly intervals from February 1980 through December 1986, a 14.5-km section of central California coastline was systematically surveyed for beach-cast carcasses of marine birds and mammals. Five hundred and fifty-four bird carcasses and 194 marine mammal carcasses were found. Common murres, western grebes, and Brandt's cormorants composed 45% of the bird total. California sea lions, sea otters, and harbor seals composed 90% of the mammal total. Several factors appeared to affect patterns of carcass deposition. The El Niño – Southern Oscillation (ENSO) of 1982–1983 was the dominant influence in terms of interannual variation in carcass deposition. During this ENSO, 56% of the seabirds and 48% of the marine mammals washed ashore. Patterns of intra-annual variation were species specific and were related to animal migration patterns, reproduction, and seasonal changes in weather. Nearshore currents and winds influenced the general area of carcass deposition, while beach substrate type and local patterns of sand deposition influenced the location of carcass deposition on a smaller spatial scale. Weekly surveys along a 1.1-km section of coastline indicated that 62% of bird carcasses and 41% of mammal carcasses remained on the beach less than 9 days. Cause of death was determined for only 8% of the carcasses. Oiling was the most common indication of cause of death in birds (6%). Neonates composed 8% of all mammal carcasses.

scholarly journals Phylogeny and Pathology of Anisakids Parasitizing Stranded California Sea Lions (Zalophus californianus) in Southern California

2021 ◽  
Vol 8 ◽  
Author(s):  
Jerko Hrabar ◽  
Hrvoje Smodlaka ◽  
Somayeh Rasouli-Dogaheh ◽  
Mirela Petrić ◽  
Željka Trumbić ◽  
...  
Keyword(s):  
Los Angeles ◽  
Marine Mammals ◽  
Phylogenetic Trees ◽  
Care Center ◽  
Gastric Wall ◽  
Zalophus Californianus ◽  
California Sea Lions ◽  
Sea Lions ◽  
Pseudoterranova Decipiens ◽  
Bacterial Coinfection

In marine mammals, nematode-inflicted pathological lesions combined with other pathogens and factors (i.e., pollution, climate change, domoic acid poisoning events, and seasonal El Nino starvation events) negatively impact pinnipeds’ health and may cause mortality. Five California sea lions (Zalophus californianus)—a female pup, three male yearlings, and an adult female—suffered mortalities during rehabilitation at the Marine Mammal Care Center Los Angeles (San Pedro, CA). According to the necropsy reports, animals developed multisystemic parasitism as a leading cause of death, combined with malnutrition and hypoglycemia. In order to reveal host–parasite dynamics that may play a role in pinniped health and recovery, we examined the type and level of histopathological stomach lesions in California sea lions caused by anisakid nematodes. All isolated anisakids were morphologically and molecularly identified, and their phylogenetic relationships were reconstructed using the sequence of the mitochondrial COII gene. Co-parasitation of different Anisakidae spp. within the same host or lesions presented the opportunity to evaluate the existence of recombinant haplotypes and their eventual pathological pressure exerted onto host. The lesions were presented as chronic granulomatous gastritis, with moderate edema and hyperemia of the tunica submucosa and lamina propria, followed by mild, focal fibrosis of the gastric wall. Ulcerative changes with mixed leukocytic infiltrate showed to be localized, shallow, and non-perforative and with no apparent bacterial coinfection, mostly accompanied by healing granulation tissue. Isolated anisakids are grouped into three distinctively separated monophyletic clades corresponding to genera Anisakis, Contracaecum, and Pseudoterranova. Most abundant were representatives of Contracaecum ogmorhini sensu lato (55.36%), followed by Anisakis pegreffii (23.21%), Pseudoterranova azarasi (17.86%), Pseudoterranova decipiens sensu lato (1.79%), and Anisakis simplex (1.79%). Phylogenetic trees revealed no differentiation at intra-species level. Our analysis of divergence revealed Contracaecum separated from other lineages in the Jurassic period at the 176.2 Mya and Anisakis diverging from Pseudoterranova in Cenozoic period at 85.9 Mya.

scholarly journals Proteomic Analysis of Urine from California Sea Lions (Zalophus californianus): a Resource for Urinary Biomarker Discovery

2018 ◽  
Author(s):  
Benjamin A. Neely ◽  
Katherine C. Prager ◽  
Alison M. Bland ◽  
Christine Fontaine ◽  
Frances M. Gulland ◽  
...  
Keyword(s):  
Kidney Disease ◽  
Marine Mammals ◽  
Kidney Diseases ◽  
Renin Angiotensin System ◽  
Zalophus Californianus ◽  
Protein Markers ◽  
California Sea Lions ◽  
Angiotensin System ◽  
Sea Lions ◽  
Urine Proteins

AbstractUrinary markers for the assessment of kidney diseases in wild animals are limited, in part, due to the lack of urinary proteome data, especially for marine mammals. One of the most prevalent kidney diseases in marine mammals is caused byLeptospira interrogans, which is the second most common etiology linked to stranding of California sea lions (Zalophus californianus). Urine proteins from eleven sea lions with leptospirosis kidney disease and eight sea lions without leptospirosis or kidney disease were analyzed using shotgun proteomics. In total, 2694 protein groups were identified and 316 were differentially abundant between groups. Major urine proteins in sea lions were similar to major urine proteins in dogs and humans except for the preponderance of resistin, lysozyme C, and PDZ domain containing 1, which appear to be over-represented. Previously reported urine protein markers of kidney injury in humans and animals were also identified. Notably, neutrophil gelatinase-associated lipocalin, osteopontin, and epidermal fatty acid binding protein were elevated over 20-fold in the leptospirosis-infected sea lions. Consistent with leptospirosis infection in rodents, urinary proteins associated with the renin-angiotensin system were depressed, including neprilysin. This study represents a foundation from which to explore the clinical use of urinary protein markers in California sea lions.AbbreviationsRASrenin-angiotensin systemleptoleptospirosisSCrserum creatinineBUNblood urea nitrogen

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